The projected need for Indian rhesus macaques for AIDS-related research exceeds availability from current domestic breeding programs and there is an urgent need to expand breeding programs for Indian rhesus macaques for future AIDS vaccine and pathogenesis studies. Further, rhesus macaques with defined histocompatibility complex genotypes and known pedigree are becoming increasingly important for research to understand the biologic variation in the immune response. The long-term objective of this application is to expand the Oregon Regional Primate Center's specific pathogen-free Indian rhesus resource and sufficiently characterize their MHC haplotype to permit selected pedigree breeding for MHC class I alleles useful in AIDS research. The specific aims for accomplishing these objectives include intensively managing a subpopulation of the Center's SPF Indian rhesus macaque breeding colony to maximize production of genetically diverse females to expand the breeding capacity of the colony. Selective breeding of MHC-typed animals will be used to enhance production of future breeder males that are homozygous for the MAMU-A 01 allele, an important allele for assessing virus-specific cell-mediated immune function in simian immunodeficiency virus vaccine models for preventing AIDS virus infection. Breeder males that are homozygous for the MAMU-A 01 allele can be used to efficiently produce large numbers of offspring carrying the desired allele without inbreeding. The breeding colony will be initially typed for eight MHC alleles and managed for the production of MHC-defined offspring of known parentage. New sheltered field cage housing is proposed to protect the animals from infectious agents in the environment.